At present, attention is paid to organic electronic devices, such as transistors and light-emitting devices using an organic material. The organic electronic device has a merit of permitting the device itself to be bent. Among others, an electronic device using a conjugated polymer can be fabricated from a solution and thus can be fabricated at low cost. In addition, the device has a merit of permitting its area to be easily enlarged.
The conjugated polymer permits of realizing highly integrated devices such as monomolecular devices and molecular electronic devices.
An organic electronic device is generally comprised of a layer device structure with several functional layers stacked on one another, which layers have their respective functions such as electron transport and hole transport. In such a device structure, the functional layers can be freely combined, whereas a problem arises on injection of electrons or holes due to presence of an interface between layers.
Molecular electronic devices are expected to be applied to memories and sensors. However, it is difficult to achieve electric contact between an electrode and a molecule, and it is considered that long-term fundamental researches are required of realization thereof.
Under such circumstances, substituted helical polyacetylene has been proposed as a molecular electronic material of a conjugated system, which is expected to solve the above problems. The substituted helical polyacetylene is disclosed in Japanese Patent Application Laid-Open No. 2004-115628 and Japanese Patent Application Laid-Open No. 2004-027182. Polyacetylene having a pseudo-hexagonal structure and a super-helical conjugated structure due to π electrons based on a double bond is disclosed in Japanese Patent Application Laid-Open No. 2004-115628, and a polymer, which is a substituted polyacetylene having a helical structure, in which the density of the helical structure is reversibly changed by application of stimulus, and absorption/emission spectral characteristics are reversibly changed, is disclosed in Japanese Patent Application Laid-Open No. 2004-027182.
However, the substituted polyacetylene disclosed in Japanese Patent Application Laid-Open No. 2004-115628 and Japanese Patent Application Laid-Open No. 2004-027182 exhibits conductivity, but is not satisfactory for practical uses.